Casing scraper



Feb. 2, 5 o...|=. SAURENMAN ETAL ,6

CASING SCRAPER Fi l ed April 6. /I948 2 Sheets-Sheet 1 DEAN .ESAUEENMAN,

PAUL Z: JU/u'o/v,

- INVENTORS.

BY A WM x/awm,

ATTORNEY.

D. F. SAURENMAN ETAL 2,667,930

Feb. 2, 1954 CASING SCRAPER '2 sheets-sheet 2 Filed April 6', 1948 my 4g? DEAN E SAUEENMAM,

INZ ENTORS I ATTORNEY.

w 3 3 w a 7 R w 1 q a ARM fl 5 w M v 9 (0* w a 0 B w w 1 Patented Feb.2, 1954 CASING SCRAPER Dean F. Sauremnanand Paul E." Hilton, Houston,

Tex-ta lillihibcliak Oily. Glif Loa A plicatm Apmlfi; 1948I-Serial No.19,396

'3 claims (019166- 18) The present invention pertains to devices for nignihe.linnerlfwallsl il wellcasi and si I 1 ;eondyits, nid moreparticularly torl cfiqranersc. anal scraping wail-filmnon', akefqi cemet.fimudhm afl nneunlshot burrs, 5 f "'Ily t .Q l. sc cm' teriall rroml.the rwlalllof ichl i l ita s;-

iDevices are known for removing the above sub- 's' om wellsconduitsr.The xnaterial on the w not theeasingnmayl e d cult o dis o e pritr ay berelative y e o fmbvl A xamplena rake. otdrilling miidca ii' i's'ually bedislodged. without diflicultyn h e nlsllqtl h!! ay.., e.qu r repeated l'f dr' s pin ac io 5 b eiore their slight, h

f bh ri z esee in risrcmoved. Asw q ll yl bi a lfibieqtcitm pr s ninvefition l p lf e e l mp qvedrcas na.scrap r v i h ca e 1 92 1 vih fiustances from, the l'of the yvellqghd lllfgll h either; longia-fi i ilgimbtion, o lrqtamme. 0.1 Thus, certain. asil 'r' o 'afi cas n coa ngs.h asdrillingl mud; can be cleaned frgnr the, casing wallkduring therunning of. the scrap onjhe drillingstrin v down" through the con uit the enti re circum; 2 fe'ren'ceof the casing: ihacleaned HOWevenW oi s al cs tanqehei e en eun e zdrmr i s o the sc ping 9l ,-,Qr .ii the. scrapn W01 l i 'd e irely. its-e r ,bc.; Qt tedrto.re-r. move the resistancecause. result,, it is 111.11.? necessary to rotate the tool during it s.entire;de- Scent thro h h Well. co du -whichv sa-tune.

consirr'rfifng' and relatively costly operation. A further 'object, ofthe inventionvisotgprQvide a casing; scraper wl'iose 'cutt blades-.are.so;.; ou e as olpb fg t jw .a 1 scrapmainstrumentalityduring'longit'udinal movement, of thew ap r o h h weltas ng a in 'jit rti n. i fi l r asins-l. 4

Yetanother object: the invention is to pro- 40 vide a casingsc'raperhaving ja ing blades providing'j'complete circurnierential-.. contactwith theinner siirfaee o; the casing, An he o t 'o' e inv c icnr s to. pvid a casing" scraper whose, getting a blades perfprrri A5 ashearingfaction on the material beingremqved, from'the casing duringboth longitudinal movement and rotation of'the 'ca'sing scraper within UI 5' J; 1:; 1;: :1

Yet a further object'of the invention is to provide a' casing, scraperwhose; blade are capable of performing their cutting andcleaning ,operand r n upwa i ,dQWQWard i cr ment-.1 theicasingfar'id also upon rotationwithin. ,the casing. v f .t

Still another object'of the invention is to provides. casing scraperwhich operates smoothlyw and without any tendeney to wobbletorschatter;Another objector the ventionuisflto provide, a cas'ingl' scraper havinga plurality 0i icuttingrrfifl thertubula'r. string bn which it is; runin -th wjel' 'touher understood that-this detailed description'is --part s,shown.in sections-i the. adjacentcv drill'rpipe section; Cai n) imayalso? pluralitrptscrapa..-

' 'v fii :cfl'uid thengrproceeds upwardlpraround r s ts are d sc s,

or scraping blades disposed at an angle and arranged in suchvmanner-asto -eliminateany tend encyof the scraper to rotate asit is being inroroiitof-the -casing,;;-thereby preventing jinad z vertent disconnectionof the casing scraper from Thislinvention possesses many otheradvantages, and has other objects which may be made more clearlyapparent from; a -=consideration-got one of itsiembodimentsv For thispurposeyaformf is shown in. the drawings-' acoompanying--'"andt formingpart of the present=specifiationz Thififij form. will nowbe describeddetailf i ll-rlstrating' the-general principles of the invention but, it

not, to; be. taken in: a limiting---sense,=--sinqe-wth scope of .theinvention is best defined by-the appended claimsm- Referring torthedrawings: Figpr lllisasside elevatiomof a casing scraper disposed-withinrah-casing section; parts;- bein showninsectiongr Fig,.,2. is anenlarged fragmentary side elevation ofv part of the casing scraperewith-certain Figsnioandjlare sections taken along the 1ines-= 3.--3,;4l;'-4'andr5.a5, respectively en Figs The .device;A disc1osedthedrawingis-a eaing scrapenadapted rotor be in-'-awell casing-r lilQIAor similamvell conduitB on the lower end of:. a tubular.string.:.of;-.-dril1; pipe G came-dike; runningeto the t0p=.o;ttheiwellrborefl The may I body Law; the casing scraperisgenerallyttibular r mior m; and;hasflanluppera inill threaded into be provi dedrwithr-a lower threaded box IZeadapteda to be secured to the pin end l3of a lower drill t 1 1 .Ihemasi-na scraper-hang be rused dn theahsenceof arlowehdrill bitifidesireds A ai AQFMIQLpa age llinextendsthrough the body 9 pc m tzdrillingefluid ormther rcirculating ud; o e -pumped downsthroughizth'ei string'mf d ill 9 .1 andthroughthegbodyzcm fora-discharge from then-lowergend OfBJthEJ-zlrttflit omeezh qmrlfi and drilL-pipe String-.Q. mzth'itopiof the well bore. As iswell known, such circulating fluid carries; the cuttin seorgscrapingswither-top bore and;maintains theicutting :po toc1=- --comparativelycleam-cond y h as a plurality of sets l6, l1,

l8, 19- Of ap r bledcs :2

vit i a1 andfinclined-with respect to, the axisloi theb or tothe've'rtical. l lachgbladeismtged out 1y of the groove by one or morehelical compression springs 22 bearing against the base 23 of the grooveand extending into pockets 24 in the inner portion of the blade 20, forbearing action against the bases 25 of the pockets.

The helical springs 22 urge each blade 23 outwardly and yieldably intocontact with the inner Wall of the well casing B, or other conduit to becleaned. Because of the angularity of the cutter or scraper blades 20,and in order to obtain their full bearing against the casing wall, theirouter surfaces 26 are formed to lie upon the surface of an ellipse. Theouter surfaces are preferably hard-faced with suitable material 27, suchas tungsten carbide, to provide a plurality of cutting edges or surfaces28, 29 on opposite sides of each blade. These surfaces or edges are botheffective to clean the inner wall of the well casing. Actually, in Viewof the surface contact between the cutter edges 28, 29 and the casingwall, the outer surfaces of the edges preferably coincide with anellipsoidal or barrel shaped surface.

order to center the casingscraper in the well casing, a plurality ofscraper blades 2|! is included in each set It, ll, IS, IS. As disclosedin the drawings, the provision of three blades 20 in each set, spaced120 degrees apart, serves as an effective means of centering the scraperbody I0, and the tool itself, in the well casing. The number of blades,of course, can be varied without departing from the present invention.

Outward movement of the inclined blades 23 in each set under theinfluence of the springs 22 is limited by engagement of the stepped,upper and lower terminal portions 30, 3| of each blade with suitablestop devices. In the present instance, these devices are shown asconsisting of segmental rings 32 fitting within peripheral grooves 33 atthe upper and lower ends of each set of blades. The rings overlie theterminal portions 30, 3|, and are secured to the body H] by screws 34 orthe like. Each ring has inner recesses 35 within which the terminalportions 30, 3| of a blade 20 is received, in order to permit the innersurface 36 of the ring to bear snugly against the base 3'! of theperipheral groove 33, and insure firm attachment of the ring to the bodyI0. Each ring 32 is composed of a plurality of segments 38, whose ends39 are mutual- 1y overlapped to afford a snug fit between the parts.

In view of the provision of a plurality of sets l6, l8, l9 of scraperblades on thebody It, the intermediate segmental stop or retainer ringsing to the casing wall, insuringrsnug engagement with the latter at alltimes.

The sets of blades l6, l1, l8, |9 are arranged to overlap each othercircumferentially of the body l0. Collectively, the sets of bladesextend around the full circumference of the body and well casing. Thus,as specifically shown in the drawings, each set consists of threecutters 20, spaced substantially 120 degrees apart. Due to theirinclination, the blades of each set will contact the casing wall along asubstantial portion of its circumference. Since four sets of blades aredisclosed, the blades of each set will engage the casing along a totalof at least 90 degrees of are. This figure is preferably somewhatgreater than 90 degrees to obtain some circular overlapping between theblades of each set. Adjacent sets of blades are also disposed out ofphase with respect to each other substantially 90 degrees. Since foursets are illustrated in'the drawings, the disposition of the sets out ofphase by 90 degrees in the same direction will insure that the bladescollectively contact the full circumference of the well casing. V

For reasons to be specified below, it is preferred that alternate setsof blades, or half the sets of blades, be inclined in oppositedirections as will be clear from an inspection of Fig.1, wherein sets itand iii are inclined in the opposite direction with respect to sets iiand I9.

It is to be understood that the extent of circumferential contact withthe casing by the 32 may serve to hold the adjacent ends of two Sets ofblades disposed within the body, as will be evident from Fig. 1. Ofcourse, the inclined grooves 2| extend into the peripheral grooves 33,in order to permit free sliding movement of the blade terminal portions30, 3| to and from the stop rings 32.

When the casing scraper A is fully assembled;

with the blades 20 unconfined by the casing 13, the springs 22 urge thecutter blades outwardly to the fullest extent, as determined byengagement of the terminal portions 30, 3| with the segmental rings 32.The cutters 20 are then retracted against the force of the springs 22vand are placed within the casing B to be cleaned. The walls of thecasing hold the blades inwardly against thespring force and space theirterminal portions 30, 3| inwardly of the stop rings 32. As a result, theblades 20 may yield in conformblades in each set; the angulardisplacement, or out of phase relationship, between the sets of blades;the angle of inclination of the blades; and the number of blades can bevaried without departing from the invention.

In view of the circumferential overlapping of the sets of blades withrespect to one another, downward movement of the tool A within thecasing string 13, through the aid of the drilling string C will causethe blades to shear any cake of material that may coat the casing wall.This shearing action will occur because of the angle at which the blades28 are disposed. It will occur without rotation of the tool A. As anexample, a cake of drilling mud is ordinarily readily removable from thecasing wall, and such cake will be entirely removed through the merelongitudinal movement of the tool A through the well casing B.

In the event that descent offthe tool A Within the casing B is arrestedby an obstruction which the blades 26 are unable to shear through merelongitudinal movement of the tool, the drilling string C and easingscraper A may be rotated to bring the blades 2t repeatedly into shearingcontact with the obstruction, until the obstruction iscompletelyremoved. Such obstruction might consist of a sheath ofhardened cement on the casing wall; or of gun shot burrs formed on theinside of the casing as a result of the shooting of bullets through thecasing during a. gun perforating operation; or the obstruction mayconsist of one or more bullets which may not have passed through thecasing, but, instead, project inwardly into it. During rotation of thetool, the angle at which the blades 20 are set causes them to perform ashearing action on the material extending inwardly of the casthe casingsnugly regardless of variation in the casing wall. The contacting of theblades 29 with the casing B at many points insures smooth operation ofthe tool, as well as the elimination of any tendency for the tool towobble or chatter. In addition, the arrangement of the sets of blades sothat they are alternately angled in opposite directions eliminates alltendency for the scraper to rotate as it is being run in or out of thecasing. The angling of all blades in the same direction might produce atendency for the body to be unscrewed from the string of drill pipeduring either raising r lowering of the tool within the well casing. Thealternate angling of the blades in opposite directions neutralizes suchtendency to rotate.

The double cutting edge 28, 29 on each blade, which, in effect, providesa cutting edge on both the upper and lower surfaces of each blade,enables the tool to perform a cutting or cleaning action during itsupward longitudinal movement in the well casing, as well as during itslowering in the well casing. A double cleaning action is thus providedduring the lowering of the well tool from the top of the well bore, andalso during. its removal from the lowermost level in the casing to thetop of the well bore. Assurance is, therefore, had of a casing stringwith a relatively clean inner wall surface.

The inventors claim:

1. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having sets of longitudinally spaced grooves, thegrooves of one set being inclined with respect to planes in which thebody axis lies in the opposite direction from the grooves of the otherset; cutter blades slidable laterally in the grooves of each set; andmeans in said body for urging said blades outwardly of said body; thedisposition of said cutter blades in said oppositely inclined groovesminimizing the tendency of said main body to rotate with respect to thedrilling string to prevent inadvertent disconnection of said main bodyfrom the drilling string.

2. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having sets of longitudinally spaced grooves, thegrooves of one set being inclined with respect, to planes in which thebody axis lies in the opposite direction from the grooves of the otherset; cutter blades slidable laterally in the grooves of each set andcollectively disposed around the entire circumferential extent of saidbody; and means in said body for urging said blades outwardly of saidbody; the disposition of said cutter blades in said oppositely inclinedgrooves minimizing the tendency of said main body to rotate with respectto the drilling string to prevent inadvertent disconnection of said mainbody from the drilling string.

3. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having sets of longitudinally spaced grooves, thegrooves of one set being inclined with respect to planes in which thebody axis lies in the opposite direction from the grooves of the otherset; cutter blades slidable laterally in the grooves of each set, saidblades having outer scraper edges substantially conforming to a portionof an elliptical curve; spring means in said grooves engageable withsaid blades for urging said blades outwardly of said body; and stopmeans common to adjacent sets of blades for limiting the extent ofoutward movement of the blades in said adjacent sets.

4. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having sets of longitudinally spaced grooves; cutterblades slidable laterally in the grooves of eachset, said blades havingouter scraper edges substantially conforming to a portion of anelliptical curve; spring means in said grooves engageable with saidblades for urging said blades outwardly of said body; and stop meanscommon to adjacent sets of blades for limiting the extent of outwardmovement of the blades in said adjacent sets.

5. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having sets of longitudinally spaced grooves; cutterblades slidable laterally in the grooves of each set, said blades havingouter scraper edges substantially conforming to a portion of anelliptical curve; the outer scraper edges of said blades collectivelybeing disposed around the entire circumferential extent of said body;means in said grooves engageable with said blades for urging said bladesoutwardly of said body; and stop means common to adjacent sets of bladesfor limiting the extent of outward movement of said blades.

6. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having a circumferential groove and sets oflongitudinally spaced grooves on opposite sides of said circumferentialgroove and extending thereinto, the grooves of one set being inclinedwith respect to planes in which the body axis lies in the oppositedirection from the grooves of the other set, the grooves of one setbeing offset with respect to the grooves of the other set; cutter bladesslidable laterally in the grooves of each set, said blades having outerscraper edges substantially conforming to a portion of an ellipticalcurve; means in said grooves engageable with said blades for urging saidblades outwardly of said body; and stop means in said circumferentialgroove common to adjacent sets of blades for limiting the extent ofoutward movement of the blades in said adjacent sets.

7. In a casing scraper: a main body adapted for attachment to a drillingstring, said body having a circumferential groove and sets oflongitudinally spaced grooves on opposite sides of said circumferentialgroove and extending thereinto, the grooves of one set being ofiset withrespect to the grooves of the other set; cutter blades slidablelaterally in the grooves of each set, said blades having outer scraperedges substantially conforming to a portion of an elliptical curve;means in said grooves engageable with said blades for urging said bladesoutwardly of said body; and stop means in said circumferential groovecommon to adjacent sets of blades for limiting the extent of outwardmovement of the blades in said adjacent sets.

DEAN F. SAURENMAN. PAUL E. HILTON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,809,975 Kattrein et a1. June 16, 1931 2,210,824 Walker Aug.6, 1940 2,275,939 Baker Mar. 10, 1942 2,295,058 Smethers Sept. 8, 19422,326,528 Festervan et al. Aug. 10, 1943 2,424,027 Gist July 15, 19472,464,390 Hammer Mar. 15, 1949 2,472,749 Lake June 7, 1949

